Instrument for measuring and correcting errors of gun-fire.



No. 858,297. PATENTED JUNE 25, 1907.

J. L. LATIMBR. INSTRUMENT FOR MEASURING AND CORRECTING RRRoRs 0F GUN FIRE.

APPLIOATION P LED HAY 8,1906.

IIIIIIIJMIMIM I! J] l I ll )fl Pig m ES: 16 R [NI/ENTOR 5% Maxim Llzzfmer BY Alzomey UNITED STATES PATENT oFFIoE.

JULIAN L. LATIMER, OF WASHINGTON, DISTRICT OF COLUMBIA.

iNSTRUMENT FORTVMEASURING AND conntcuue ERRORS 0F GUN-FIRE.

Specification of Letters Patent.

Patented June 25,1907.

application filed May 8,1906. Serial No- 316,840.

' and particularly for determining the lateral error of a shot relative to the object at which it is aimed. I

The invention has for an ob ect to provide.

in an optical instrument a transparent scale having successive graduations thereon corresponding with those of a piece of ordnance together with a hair line crossing said scale and means for adjusting said scale laterally of said line whereby the angular lateral distance of the fall of the shot from the object can be instantly read from the scale, and the latter adjustedin azimuth to exactly correspond with each movement of the gun sight whereby successive errors can be read in the same terms as the lateral graduations of the sight, and the reading of the scale applied directly to the sight scale of the gun without calculations and without reference to tables.

The invention has for a further object to provide a novel and improved construction for mounting the adjusting scale, and also a graduation of the scale in fixed angles of 3 and 26 so that if the distance is known, the lateral error can be readily determined as each division of the scale will subtend a chord 1 1000 of the distance.

Other and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined by the appended claims. I

in vthe drawing :Figure 1 is a plan of amonocular telescope with parts in horizontal section; Fig. 2 is a vertical section on the line 2--2, Fig. 1.; Fig. 3 is an enlarged elevation of the scale, and Fig. 4 is a diagram showing the angle measured by the scale.

Like numerals of reference indicate like parts in the several views of the drawing.

This invention is adapted for application to any character of optical instrument, but for the purpose of illustration is herein shown as used in connection with a monocularglass and arrangement of or telescope 1 havin the usual construction vided with the frame 2 extended laterally thereof at each side where handles 3 are mounted so that the instrument may be conveniently grasped and held by both hands of the observer, while the eyepiece 4 thereof is provided with the rubber guard 5 of ordinary construction, which may be firmly pressed against the face so that the eye will be at the proper distance from the eyepiece. At one end of this eyepiece a casing 6 is mounted and adapted-to carry the transparent scale 7 which is fitted in the focus of the object glass and provided with horizontally arranged graduations S thereon. These graduations corres end with those of the azimuth scale lenses therein, and pro-' for in icating the lateral sighting of a gun or end against the frame 9, while its outer end is provided with a milled head. 12 adapted to be readily moved by the thumb of the ohservers hand. At the opposite side of the casing 6, a tubular shell 13 is secured and within the same a restoring spring 1-1 is disposed, which spring is provided at its inner end with a contact point 15 bearing upon the end of the frame carrying the transparent scale 7. At one side of this scale a hair line 16 is secured in either lixed or adjustable position, but is scale is mounted in the frame 9.

relatively fixed to the movement of the scale upon the same. This hair line indicates and corresponds with the pointer of the gun or piece of ordnance to be fired. The graduations upon the transparent scale are in angles of 3 26and numbered consecutively from left to right, as shown in Fi 3, every fourth graduation being numbere and the middle number correspondin with the center of the field when the grac nations are centered.

Each graduation of the scale is a chord of the 'millieme and is e ual to 1/1000 of the radius of its circle, as t e lateral deviation can al ways be given in yards, for example, the lateral deviation in yards for .one millieme being 1 1000 of the distance, if the range is 2000 yards, the lateral deviation 2 milliemes, the lateral error will be 4 yards.

In the diagram shown in Fig. 4, the target IIO proper position and sights the hair line centrally upon the target, it being understood that the graduations upon the scale correspond to those upon the lateral or azimuth scale of the gun. Upon firing the first shot the flight of the projectile is observed and its point of contact noted upon the scale so that the graduation thereof may be instantly read and the distancefrom the hair line, which in dicates the point of the target desired to be hit, designates the lateral deviation of the shot. The observer then signals to the gunv nor the number of'the graduation indicated upon his scale and the azimuth pointer on the -gun is adjusted to the same number. The observer then moves the scale by the lateral adjusting means so.as to bring the graduation of the point of contact just noted into alinement with the hair line. He then notes the second shot, in the same way keeping the hair line upon the point to be hit and noting the fall of the projectile on his 'scale,

the number of the graduation ofithe scale onwhich the second shot falls is then signaled to the battery-wherethe sight -is then acoordingly corrected and the observers scale is again moved until this graduation coincides with the hair line. By this method the horizontal scale is always the .same as the azimuth scale of the gun, and the observer can signal to the gunner exactly the mark on the sight scale to which the azimuth pointer must be set to correct the error of the last shot. The hair line indicates the center of the target when sighted thereon and the graduation at which the projectile contacts indicates the angularerror of that shot so that a movement of the gun and scale to bring the projectile graduation in alinementwith the hair line produces an absolute correction of the error in laying the gun. It is not necessary to remember the figures of the last order, or whether they be to the right or left of the hair line, and the possibility of error in the excitement of action is completely removed. For instance, if one of the gunners fails to get the signal, the next subsequent signal will give him the proper position of the sight pointer to correct all previous errors. In usin this instrument it is only necessary that t e ofiicer observe the fall of the shot so that the lateral errors can be immediately corrected without calculation or reference to tables.

terms as the lateral graduations of the sight and'the reading of the scale applied directly thereto.

While reference has been made to the readingof lateral deviations of .a shot, the invention is not confined to a deviation in a horizontal plane at either side of the target, but also comprehends the reading of such deviations in any direction from the center of the target.

Having now described my invention and set forth its merits, what I claim and desire to secure by Letters Patent is 1. In an instrument of the class described, a transparent scale provided with indicating characters extending laterally of the instrument, a hair line crossing said scale, and means for adjusting said scale laterally of said line.

2. In-an instrument of the class described, a transparent scale graduated to correspond with the lateral or azimuth scale of a piece of ordnance, a hair line crossi responding to the pointer o the sight, and means for adjusting said scale laterally of said line.

3. In an instrument of the class described,-

a transparent scale provided with successively increasing ind1catin characters ex tended laterally thereon, a airline crossing said scale, and means for adjusting said scale laterally of said line. I a

4. In an optical instrument of the class described, a casing disposed laterally of the eyepiece thereof, a graduated sliding plate mounted within said casing, a hair line supported by the casing at one side of said plate, an adjusting screw having a threaded bearing at one end of said casing and adapted to move said plate in one direction, and a restoring spring at the opposite sideof the casing adapted to move said plate in the opposite direction.

5. In an optical instrument of the class described, a transparent scale graduated to indicate equal angles radiating laterally from the optical center of the instrument, a hair line crossing said scale, and means for adjustin said scale laterally of said line.

6. l n an optical instrument of the class described, a' transparent scale graduated to correspond with the lateral'graduations of a gun sight and rovided with controlling means whereby t e angular lateral distance of the fall of a shot from the object aimed at may be read directly from said scale in the terms of the sight graduations.

7. In an optical instrument of the class described, a transparent scale graduated to correspond with the lateral graduations of a said scale corgun slght and provided with controlling I In testimony whereof, I afiix my signature means Iconstructed1 to 1adjust ia'id scale in in presence of two Witnesses. azimut across a air ine to t e successive movements of the gun sight whereby each 7 JULIAN LATIMER' successive angular error in the fall of the shot Witnesses:

may be read directly from said scale in the JOHN L; FLETCHER,

terms of the lateralzgraduations of the sight. ALFRED T. GAGE. 

